Stern-tube for screw-propeller shafts.



PATENTED MAY 10, 1904.

J. STEPHENS.

STERN TUBE FOR SCREW PROPELLER SHAPTS.

APPLIOATION FILED JAN. 31, 1903.

N0 MODEL.

fizrenfor: AM MW am WM 5%) Patented May 10, 1904.

PATENT OFFICE.

JAMES STEPHENS, OF STONEHOUSE, ENGLAND.

STERN-TUBE FOR SCREW-PROPELLER SHAFTS.

SPECIFICATION forming part of Letters Patent No. 759,323, dated May 10, 1904.

Application filed 'muary 31, 1903. Serial No. 141,372. (No model.)

To a whom it may concern:

Be it known that LJAMES S'rnrnnnaa citizen of the United Kingdom of Great Britain and Ireland, residing at Stonehouse, in the county of Gloucester, England, have invented Improvements in Stern-Tubes for Screw-Propeller Shafts, of which the following is a specification.

The object of this invention is to provide a stern-tube that will perfectly protect the propeller-shaft from corrosion and at the same time dispense with the costly shaft-casing and provide an eflicient arrangement for lubrication with oil or other like lubricant.

In carrying out this invention I construct a metal tube, hereinafter called the stern-tube, with arrangements forsecuring it to the sternframe and to a transverse bulkhead of the ship, according to well-known plans. This stern-tube I bore for the greater part of its length of such a size as to be a good working fit, in which the propeller-shaft may revolve, or of such size larger than the propeller-shaft as to admit of a removable bush being fitted in the stern-tube. I. bore the after end of the stern-tube of such size larger than the propeller-shaft as to allow of the insertion of a metal sleeve attached to the propeller-boss and also (outside of this sleeve) to admit two packing-rings, either of the description known to hydraulic engineers as U-leathers or of the description known as hat-leathers, but preferably the latter, and they may be of leather or of any other suitable material,provided they are of the before-named form. In a portion of the length of this enlarged bore I cut a screwthread, in which I fit a metal nut for securely retaining the said packing-rings in position, or otherwise they may be secured by a gland and bolts. The object of the aftermost of the before-named packing-rings is to secure the exclusion of water from the interior of the stern-tube, while the forward one is for retaining oil or some like lubricant within the stern-tube. I bore the forward end of the stern-tube of such size larger than the propeller-shaft as to admit of fitting one packing-ring of a like description to the beforenamed packing-rings and a nut for retaining it of like description and in a similar manner to that by which the packing-rings are retained in the after end of the stern-tube. The object of this packing-ring is to retain the oil or some like lubricant within the stern-tube. I also lit a tube into the top of the stern-tube for the supply of oil or some like lubricant and a similar tube into the bottom of the sterntube for drawing off the lubricant as may be desired.

The above description will be better understood by reference to the accompanying drawing, which is a vertical longitudinal section of the stern-tube and of portions of the sternframe and transverse bulkhead and also of portions of the propeller-shaft and propellerboss, not in section, showing the improvements.

1 is the stern-tube; 2, screw-propeller shaft; 3, screw-propeller boss; 1, the packing-rings; 5, a loose metal ring separating the packingrings; 6, nuts for securing the packing-rings; 7 metal sleeve attached to the propeller-boss; 8, nut for securing stern-tube to stern-frame; 9, stern-frame; 10, transverse bulkhead; 11, oil-tubes.

What I claim as my invention, and desire to secure by Letters Patent, is-

The outer tube in conjunction with the metal sleeve attached to the propeller-boss, the U or hat shaped packing-rings of leather or other suitable material, and the nuts for securing the same, substantially as and for the purpose specified.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JAMES STEPHENS.

Witnesses:

A. GTE, CnoIL Gr. PALIN. 

